SU910433A1 - Unit for moulding polymeric film - Google Patents

Description

(5) INSTALLATION FOR FORMING POLYMER FILMS

The invention relates to the design of installations for the half-substance of semi-permeable microporous films used in the microbiological industry from polymer solutions. The invention can also be used in microelectronics and the electrovacuum industry for the manufacture of filter materials for cleaning photoresists, manufacturers, etchants, gases, and the like.

A known apparatus for forming polymer films, comprising a pressurized injection funnel in communication with a liquid container, a pneumatic system for expelling the latter from the funnel, a substrate and a dosing device.

The disadvantage of this technical solution is the complexity of the design, due to the presence of a metering device in the form of a gate-metering device (impeller) or bilateral peristaltic pumping. Besides

TOGO 8 in this installation there is no vacuum degassing of the applied solution, therefore air bubbles in the solution, as well as those formed as a result of the operation of the mechanical dispenser and pneumatic system, fall along with the solution on the substrate, which leads to defects on the film, reducing the quality of the resulting film.

The need to change the substrate, the torus is not infinite, reduces the performance of the installation.

The closest in technical essence to the invention is an installation for molding a polymer film,

IS containing die, casting slave. which element is in the form of a flexible endless substrate of an oval contour; a support element mounted on a horizontal shaft 2.

20

The disadvantages of the last installation are the inconvenience of the linear speed of movement of the casting working element due to slippage 3

its relative to the supporting element, made in the form of a drum; mechanical damages and deflection of the casting working element, due to its thickness (0.1-0.6 mm) and low hardness (clamping, scratching) during operation of the installation; reduces the quality of a formable especially microporous films; the inability to change the geometry of the casting work item when changing the viscosity of the source material, which limits the technological capabilities of the installation.

The purpose of the invention is to increase the quality of the microporous film and expand the technological capabilities of the installation.

This goal is achieved by the fact that in an installation for forming a polymer film containing a die, a casting workpiece in the form of an endless oval contour substrate, mounted on a horizontal shaft, according to the invention, the support element is provided with rollers skirted by flexible endless substrate.

In addition, one of the rollers of the support element is installed in the zone of contact of the die with a flexible endless substrate.

FIG. 1 shows a general view of the installation; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. 2

The installation for forming a polymer film contains a casting working element in the form of a flexible infinite thin-walled substrate 1 of an oval contour with a polished surface. Substrate 1 pomeiGena in the bath 2 with a precipitator, the level of which is maintained constant.

In the upper part of the substrate 1, a filler 3 is installed, intended for applying (spreading) the polymer solution onto the substrate 1. The working cavity of the die plate 3 is communicated via tube k with a loading container 5 equipped with a shut-off valve 6. Loading capacity 5 for evacuating the polymer solution the purpose of removing air bubbles and maintaining a constant level of solution in the die 3 during

the whole process of forming the film is provided with a fitting 7 for communicating its cavity with a vacuum source and is mounted on the bracket 8. The bracket 8 is mounted to move over the bath 2 along the cylindrical guides 9 and has a mechanism 10 that allows the loading tank 5 to be removed and rotated

o and vertical movement.

Next to the spinneret 3, a cleaner 11 is installed, intended for cleaning and drying the surface of the substrate 1 and preparing for molding on a non-film. The cleaner 11 has the means 12 and 13 of mechanical cleaning (with the help of water and alcohol) and the means 14 of the final vacuum cleaning (drying) with a clean, oilless vacuum and is mounted on the bracket 15.

On the guides 1b, the extending 17 and pinch 18 rollers are mounted, by means of which the formed polymer film, which already has sufficient strength, is separated from the surface of the substrate 1 and passes a row of washing baths (not shown). The mechanism 19 winding film is installed in the last wash tub 2P. The winding of the film is carried out at a constant linear velocity and under a layer of water. All the mechanisms and units of the installation are mounted on the base plate 21, fitted with windows a.dl of baths, sealed around the perimeter and ensuring the tightness of the working area of the forming film.

For ease of film transfer to the pull rolls 1 / baths, they can be removable.

Horizontally located shaft 22 is placed in a bath of 2 bearings and supports 23 and is provided in the middle part with a support element 2k with axles 25 on which fluoroplastic bearings 2b and rollers are mounted

27, envelopes of the substrate 1.

0 In order to periodically rotate the support element 2k together with the shaft 22 (if necessary, change the geometry of the substrate 1), the latter is equipped with a gear 28 connected with fur

5 turning point (not shown).

To move the support 1, equidistant to the contour of the reference section

five

element 2A with rollers 27, one of the ends of the substrate 1 is made with grooves 29 in which the pins 30 of the block shafts 31 are mounted on the shaft 22. The gear-box 3 receives rotation from the actuator 32. 33- Sealing the rolls in the bath is carried out by seals З, 35 and 36.

In the free undeformed state, the dimensions of the substrate 1, having the form of a cylindrical shell, are as follows: outer diameter 315 mm and wall thickness 1.5 mm.

The operation of the installation is carried out as follows.

Before starting work, the required thickness of the formable film is determined, which is determined by the magnitude of the rise of the knife of the die 3.

Further, when the shut-off valve 6 of the loading tank 5 is closed, the polymer solution is poured into it in the quantity required for the installation to work during the shift. Then the loading tank 5 is sealed, the source of vacuum is turned on. After evacuating the polymer solution, the shut-off valve opens; pan 6, the solution is poured into the spinneret 3 and fills it to the lower end of tube i.

The drive 32 of rotation of the substrate 1, the pulling rollers 17 and the winding mechanism 19 are turned on. Under the total (hydrostatic + air) pressure of displacement, the polymer solution through the slit of the nozzle 3 enters the moving surface of the substrate 1.

The displacement pressure is relatively constant (the level of the solution in the die is 0.5 mm), since if the level of the polymer solution is lowered, continuous feeding of the polymer solution from the loading tank 5 takes place: the air volume enters the tube 4 through its lower end, then up the tube into the loading container 5, increasing the pressure above the polymer solution.

The constant level of the polymer solution in the die 3 ensures that it is evenly distributed on the sub433 .. 6

spoon 1 and the stability of the thickness of the resulting film.

The film is formed on the surface of a flexible thin-walled substrate 1, whose geometry can be changed, changing the shape of the support element 2 with the rollers 27 on which it is installed.

The shape of the support element 2 with rollers 27 may be having a along a second-order curve (parabola, valvent, etc.) having portions of different curvature. In addition, the geometry of the substrate 1 can be changed

5 by rotating the horizontal shaft 22, on which the supporting element 24 is fixed, supplying areas of different curvature under the die 3. Due to this, it is possible to form films on the same installation from polymer solutions of different viscosity, polymer concentration and chemical composition, t . the technological capabilities of the installation are expanded, and the use of low-curvature or flat areas of the substrate prevents the polymer solution from flowing downwards, thereby providing

0 uniform thickness of the film during its solidification and its further passage through the bath 2 with the precipitator. The use of the invention provides an increase in the uniformity and quality of the resulting film, the percentage yield of suitable films; expansion of technological capabilities of the installation, which is especially important for experimental and laboratory production;

Claims (1)

1. An installation for forming a polymer film containing a spinneret 5 a casting working element in the form of a flexible endless substrate of an oval contour, a supporting element mounted on a horizontal shaft, characterized in that, in order to improve the quality of the microporous film and expand the technological capabilities of the installation, the supporting element is provided with rollers mounted on it with the possibility of rotation, envelopes by a flexible infinite finite substrate. 2, Installation according to claim 1, characterized in that from the rollers of the support element is installed in the zone of U7 + Z3 infinite substrate, USSR Author's Certificate on substrate.1 614823, cl. In 29 D 7/02, 1977. and 2- USSR Author's Certificate Sources of information, N 530805, class B 29 D 7/00 1975 taken into account in the examination (pr1totip). 6 25 IkFig.1 50 J / 3 & 7 /, ig.2 4 2ff